Aggregates

exists()

Returns boolean indicating if any rows match. Uses SELECT EXISTS() for optimal performance.

const hasAdmin = await db.users.where({ role: 'admin' }).exists();
// true or false

count()

Table-level count

const result = await db.users.count({ status: true });
// { success: true, data: [{ count: 42 }] }

Chainable count

const result = await db.users.where({ status: true }).count();
// { success: true, data: 42 }

distinct()

Get distinct values for a column.

const roles = await db.users.distinct('role');
// { success: true, data: ['admin', 'member', 'viewer'] }

Performance Tips

1. Use first() instead of many()[0] - Adds LIMIT 1 automatically
2. Use exists() for boolean checks - Uses SELECT EXISTS() subquery
3. Use select() to limit columns - Reduces data transfer
4. Use whereIn() for batch lookups - Single query instead of N queries
5. Batch inserts - Pass array to insert() for single statement